Improvement in try-squares



`W.V H. GPER. Try-Squares.-

VNO. 142,557, Patented September9,873

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UNITED STATES PATENT EEIcE.

WILLIAM H. COOPER, OF LOWELL, MASSACHUSETTS.

HMPROVEMENT IN TRY-SQUARES.

Specification forming part of Letters PatentNo. 142,55*?, dated September 9, 1873; application filed J une 9, 1873.

To all 'whom tt may concern:

Be it known that I, WILLIAM H. COOPER, ot', Lowell, in the county of Middlesex and Commonwealth of Massachusetts, have invented Acertain Improvements in Squares, of which the following is a specification:

My invention relates, principally, to the combination with a square'of a supplementary blade, as and for the purpose hereinafter described.

The accompanying drawings represent my invention. I

Figure-1 is a perspective view of a trysquare, having attached to it-s blade a supplementary blade; also, a yoke supporting a thumb-screw; also, a gib to receive the thrust ot said screw. Fig. 2 is a perspective View of the same, the yoke being attached to a differcnt part of the blade.

`A is the beam of a try-square. B is the blade of the same. C is a plate, which should be of the'same thickness as the blade B, and has parallel sides and right angles, and may be in size and shape the same as said plate B. To this plate or supplementary blade C, by rivets or otherwise, is attached the Ushaped piece or yoke D. The arms of the yoke D are slitor sawed through to let the blade B through them, as shown in the drawings. In the middle of the yoke is a thumb-screw, E, the thrust of which screw is received upon the gib or piece of metal, F, which has a straight-edge resting upon the edge of the blade B, to protect said blade from being marred by said screw.

The principal use of the supplementary blade C is to form with the square an adjustable square, which shall have the advantages of a set of squares with blades ot'diii'erent lengths. It has other uses, however. Thus, when the supplementary blade is inthepposition shown in either of the figures, the square would indicate whether two dat surfaces not in the same plane were parallel to each other, the end ot' the blade C resting upon one ot' said surfaces, and the back of the beam A resting upon the other surface. The square, as shown in Fig. 1, would also show whether the sido of a groove was perpendicular to a plane surface outside of said groove, and this where the said groove is too shallow to receive the blade ot' an ordinary square. The square shown in Fig. 2 will indicate whether the internal angle of two plane surfaces is a right angle when at the point of intersection of the same there is a molding or other obstacle to the use of an When the supplementary ordinary square. blade C is turned end 'or end, (as it may be, since both sides of said blade C and yoke D are alike,) and the yoke is placed as near as possible to the left end ot' the blade B, said bla-de B is in effect so extended that it is possible to ascertain whether two plane surfaces which are at some distance apart are perpendicular to each other.

Various other applications ot my invention may be readily discovered by any practical mechanic.

The yoke D may be in the middle or at the end ot' the supplementary blade C; better at the end, l'lowever, as it may readily be changed end for end by loosening the thumbscrew, when the blade C will slide on the blade B.

Instead of the thumb-screw E, cams or ee' centrics may be used. v

I claim as my invention- The combination of the supplementary blade C, provided with the yoke D and thumb-screw E, with a square, A B, as and for the purpose herein described.

WILLIAM II. COOPER.

Witnesses:

ALBERT M. MOORE, J. F. FEYE. 

